Topographic Maps

USGS Topographic Maps

Dataset Basics

The Indiana Spatial Data Portal (ISDP) archive provides the USGS digital topographic maps in two different products: the digital raster graphic (DRG) legacy product and the new US Topo product. The legacy DRG's are available in TIFF format (with or without the map border) and GeoPDF® format. The ISDP archive includes the DRG 7.5-minute (1:24,000), 30 x 60-minute (1:100,000), and the 1 x 2 degree (1:250,000) series maps.

The Digital Raster Graphic (DRG) is a scanned, digital image of a US Geological Survey (USGS) standard series topographic map. The original DRG images included the full map extent and surrounding map border information. To produce the DRGe product, the USGS removed map borders and appended portions of surrounding map images to create rectangular images which are suitable for seamless tiling in a geographic information system.